Water Vapor: What It Can Do!!

[David Tanks]

FYI.

David AD4TJ

----- Forwarded Message -----

From: Dan Bathker via groups.io <d.bathker=att...@groups.io>

To: ma...@ham-antennas.groups.io <ma...@ham-antennas.groups.io>

Sent: Tuesday, August 4, 2026 at 12:00:12 AM EDT

Subject: Re: [Ham-Antennas] A question on Comet H-422

Suggestion to Prasad Agrahar (and to all, including to remind myself):

Google: "How does water vapor enter apparently sealed volumes?"

Google AI answers:

"Water vapor enters theoretically "sealed" volumes through molecular diffusion, permeation through barrier materials, and pressure-driven leaks via microscopic flaws or seals." [1, 2, 3]

Transport Mechanisms

Permeation: Water gas molecules physically pass right through solid polymer, plastic, or rubber seals and container walls on a microscopic level. [1]
Diffusion: Vapor moves across concentration gradients, seeking equal distribution from high ambient humidity outside to lower internal humidity inside. [1, 2]
Leaking: Pressure and temperature changes create micro-gaps in physical joints, O-rings, or glue lines, pulling or pushing humid air inward during thermal expansion cycles. [1]
Outgassing: Moisture trapped inside internal components, plastics, or on container walls turns into vapor over time and releases into the space. [1, 2, 3, 4]

End Google AI.

Bottom Line: (My words)

Normal daily temperature variations cause small pressure variations which "pump" water vapor even into the smallest of spaces.

Solution:

Super-Smart Techs who install cellphone tower equipment teach us:

"Use silicon grease to fill every tiny volume even in very small coax connectors."

We ham radio aficionados live in a complicated world -- so get used to it -- learn how to live with it!

Good DX

Dan K6BLG

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On Monday, August 3, 2026 at 08:07:22 PM PDT, Prasad Agrahar via groups.io <prasad.agrahar=yaho...@groups.io> wrote:

I understand, and that would happen only if there is a way for the water to enter.  But how would water enter if I seal all possible entries (all holes and gaps) with tape? It is a self vulcanizing tape that bonds tightly. 

 

 

 

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